The invention relates to an immersion measuring probe for measurement in liquids, in particular in molten metals, the probe having a carrier tube, a measuring head mounted on one end of the carrier tube, and measuring elements as well as signal lines for the measuring signals generated by the measuring elements arranged on the measuring head, wherein the signal lines are longer than the carrier tube and run from the end of the measuring head facing the inside of the carrier tube, and wherein the signal lines run through the inside of the carrier tube and are wound up inside of the carrier tube around its longitudinal axis.
Measuring probes of this type are known from U.S. Pat. No. 3,505,871. They are used for measuring in steel-converter furnaces (converters). For measurements in converters the measuring probe is dropped into the converter from a relatively large height. The signal lines are wound up on the inner surface of the carrier tube, and they automatically unwind themselves during the free fall of the measuring probes, wherein one end of the signal line is connected to the measuring head, while the other end of the signal line is either connected via a contact piece by extension lines or compensation lines or directly to a measuring and evaluation device. In this manner, several measuring probes can be stored in a magazine at a great height above the converter, wherein for the measurements one measuring probe at a time is released from the magazine and falls in free fall into the molten metal located in the converter.
Similar devices are known from U.S. Pat. No. 5,584,578, wherein the signal lines are wound up on the outer surface of the carrier tube.
Similar devices are also known from U.S. Pat. No. 5,168,764 or from I&AM, September 1993. The measuring probes disclosed by these sources are suspended in magazines, wherein it is known from U.S. Pat. No. 5,168,764 to wind the signal lines not directly around the carrier tube of the measuring probe, but instead to wind them in a separate container. This has the effect that in the magazines, along with the respective measuring probe, the supply container for the signal lines must also be mounted, so that the magazines must be designed to be suitably large.
From European published patent application EP 0 375 109 A2 a similar measuring probe is known. The measuring probe disclosed therein has a sample chamber arranged outside of the measuring head, which is mounted on a steel cable guided through a tube parallel to the carrier tube. The steel cable is wound up on a spool and can be unwound when the measuring head is lowered.